The present invention relates generally to equipment utilized, and operations performed, in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides a method and apparatus for use with two or more hydraulic fluid conduits deployed downhole.
The use of two or more hydraulic fluid conduits or lines downhole in production wells is becoming more widespread. Typically, a plurality of hydraulic lines are run from surface equipment such as a hydraulic fluid pump and associated control equipment therefor, through a wellhead and to downhole tools in a well. For example, sliding sleeves, interval control valves (ICV""s), chokes and other downhole tools may be actuated using hydraulic lines in a well.
The downhole tools may be placed in different, and potentially isolated, sections of a production tubing string. When actuated by the presence of pressurized hydraulic fluid within an associated hydraulic line, a choke or valve can be operated to control a production fluid flow rate within its associated production tubing section. This is but one example of the many ways hydraulic lines are used to actuate downhole tools and control different aspects of wells. A further example of the use of multiple hydraulic lines to control actuation of multiple downhole tools is described in PCT Application No. GB 99/02694.
Generally, when multiple hydraulic lines are used in a well, each hydraulic line must penetrate the wellhead located at the mouth of the wellbore, and must also penetrate other pressure bulkheads, such as packers and other downhole equipment, in order to reach the hydraulically actuated downhole tools. Penetrations through the wellhead and other pressure bulkheads are preferably kept to a minimum, since each penetration represents a possible leak path through a bulkhead.
Unfortunately, in the past, it has been necessary to use a penetration through a bulkhead for each hydraulic line passing through the bulkhead. This situation either requires that the number of penetrations (and thus, the number of possible leakpaths) be increased when additional hydraulic lines pass through the bulkhead, or prevents the use of such additional hydraulic lines when the number of penetrations cannot be increased.
Form the foregoing, it may be clearly seen that it would be highly advantageous to provide a method and apparatus whereby multiple hydraulic lines may be used with a single penetration through a bulkhead. Such a method and apparatus would permit an increased number of hydraulic lines to be used with a given number of penetrations. It is accordingly an object of the present invention to provide such a method and apparatus.
In carrying out the principles of the present invention, in accordance with an embodiment thereof, a method and apparatus which permits two or more hydraulic fluid paths to extend through a single penetration of a wellhead or other structure is provided which solves the above problem in the art.
According to a first aspect of the present invention, there is provided an apparatus for use with two or more hydraulic fluid conduits deployed downhole. The apparatus includes a fluid conductor which provides a respective and separate fluid path for the fluid contained within each of multiple hydraulic fluid conduits. The fluid conductor is adapted to be at least partially located within an aperture formed through a well bulkhead.
According to another aspect of the present invention, there is provided a method of passing two or more hydraulic fluid paths through an aperture formed through a well bulkhead, the method comprising locating a fluid conductor at least partially within the aperture, the fluid conductor providing a respective and separate fluid path for the fluid contained within each of multiple hydraulic fluid conduits.
The well bulkhead may be a downhole tool such as a packer, electric submersible pump or any other tool located downhole within an open or cased wellbore, or located within production tubing. Alternatively, the bulkhead may be a tubing hanger, wellhead or Christmas tree which is located at least partially outside the wellbore itself, such as at the mouth of the wellbore.
Preferably, the apparatus includes two couplings. The couplings are connected to the fluid conductor on opposite sides of the bulkhead. Each coupling provides a mechanical connection between the multiple hydraulic conduits and the fluid conductor, and further provides fluid communication between each of the hydraulic conduits and a respective one of the fluid paths in the fluid conductor.
In one embodiment, the fluid conductor has multiple bores formed therethrough. Each of the bores corresponds to one of the fluid paths through the fluid conductor. In another embodiment, the fluid conductor includes multiple tubular members. One fluid path is formed within an inner one of the tubes, and another fluid path is formed between two of the tubular members.
These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.